The present invention relates to a mutant allele of sunflower designated NSMA, which confers white seed color. The present invention also relates to sunflower plants, plant parts and seeds having the NSMA mutant allele. In addition, the present invention is also directed to transferring the NSMA allele to plants in the same species lacking the allele, and is useful for producing novel plants and varieties of sunflower having white seeds. All publications cited in this application are herein incorporated by reference.
There are numerous steps in the development of any novel, desirable plant germplasm. Plant breeding begins with the analysis and definition of problems and weaknesses of the current germplasm, the establishment of program goals, and the definition of specific breeding objectives. The next step is selection of germplasm that possess the traits to meet the program goals. The goal is to combine in a single variety or hybrid an improved combination of desirable traits from the parental germplasm. These important traits may include increased head size and weight, higher seed yield, improved color, resistance to diseases and insects, tolerance to drought and heat, and better agronomic quality.
The cultivated sunflower (Helianthus annuus L.) is a major worldwide source of vegetable oil. In the United States, the major sunflower producing states are the Dakotas, Minnesota, Kansas, Colorado, Nebraska, Texas and California, although most states have some commercial acreage.
Sunflowers are considered oilseeds, along with cottonseed, soybeans and canola and the growth of sunflower as an oilseed crop has rivaled that of soybean. The oil accounts for 80% of the value of the sunflower crop, as contrasted with soybean which derives most of its value from the meal. Sunflower oil is generally considered a premium oil because of its light color, high level of unsaturated fatty acids, lack of linolenic acid, bland flavor and high smoke points. The primary fatty acids in the oil are oleic and linoleic with the remainder consisting of palmitic and stearic saturated fatty acids.
Non-dehulled or partly dehulled sunflower meal has been substituted successfully for soybean meal in isonitrogenous (equal protein) diets for ruminant animals, as well as for swine and poultry feeding. Sunflower meal is higher in fiber, has a lower energy value and is lower in lysine but higher in methionine than soybean meal. Protein percentage of sunflower meal ranges from 28% for non-dehulled seeds to 42% for completely dehulled seeds.
In addition to its use in food and food products for humans and animals, sunflower oil also has industrial uses. It has been used in paints, varnishes and plastics because of good semidrying properties without the color modification associated with oils high in linolenic acid. It has also been used in the manufacture of soaps, detergents and cosmetics. The use of sunflower oil (and other vegetable oils) as a pesticide carrier, and in the production agrichemicals, surfactants, adhesives, fabric softeners, lubricants and coatings has been explored. Considerable work has also been done to explore the potential of sunflower as an alternate fuel source in diesel engines because sunflower oil contains 93% of the energy of US Number 2 diesel fuel (octane rating of 37). Sunflower oil has also been proposed as a source of hydrogen for hydrogen fuel cells. (BBC News, Aug. 26, 2004).
Sunflower is an annual, erect, broadleaf plant with a strong taproot and a prolific lateral spread of surface roots. Stems are usually round early in the season, angular and woody later in the season, and normally unbranched. The sunflower head is not a single flower (as the name implies) but is made up of 1,000 to 2,000 individual flowers joined at a common receptacle. The flowers around the circumference are ligulate ray flowers without stamens or pistils; the remaining flowers are perfect flowers with stamens and pistils. Anthesis (pollen shedding) begins at the periphery and proceeds to the center of the head. Since many sunflower varieties have a degree of self-incompatibility, pollen movement between plants by insects is important, and bee colonies have generally increased yields.
There are two basic types of sunflowers grown in North America: 1) oil-type sunflower used for oilseed production and 2) non-oilseed, or confectionery sunflower, used for food and birdseed. Oilseed sunflower seeds are usually smaller and black in color, whereas non-oilseed or confectionery sunflower seeds are larger than oilseed and are black and white striped.
At least 30 diseases, caused by various fungi, bacteria and viruses, have been identified on wild or cultivated sunflower, but only a few are of economic significance as far as causing yield losses. The sunflower diseases Phoma Black Stem (Phoma macdonaldii), Phomopsis Stem Canker (Phomopsis helianthi), Verticillium Leaf Mottle (Verticillium dahliae) and Sclerotinia (Sclerotinia sclerotiorum) are some of the most significant disease problems in sunflower producing areas of China, United States and Europe.
The development of a cytoplasmic male-sterile and restorer system for sunflower has enabled seed companies to produce high-quality hybrid seed. Most of these have higher yields than open-pollinated varieties and are higher in percent oil. Performance of varieties tested over several environments is the best basis for selecting sunflower hybrids. The choice should consider yield, oil percentage, maturity, seed size (for non-oilseed markets), and lodging and disease resistance.
Therefore, it is desirable to develop new sunflower types with excellent seed characteristics, such as novel confectionery sunflower seeds that are white seeded, as conferred by mutant allele of sunflower designated NSMA. It is especially desirable to have a dominant allele conferring white seed color to sunflower that is easy to transfer to different genetic backgrounds and have expression of white seed color in hybrid sunflower combinations and their progeny. A unique confectionary sunflower seed color, such as white, aids with seed sorting and breeding. Further, certain consumers find white sunflower seeds more desirable than the black and white striped confectionary sunflower seeds currently available in the market.
The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification.